PM2.5 Concentrations in the Smoking Lounge of a Cannabis Store

To assess the exposure of patrons and workers to secondhand cannabis smoke in the smoking lounge of a cannabis store, we measured airborne PM2.5, cannabinoids, and nicotine in a cannabis store and a nearby coffee shop. The PM2.5 concentration was measured with laser photometers. Air samples were collected on filters. Cannabinoids were quantified by liquid chromatography with tandem mass spectroscopy, and nicotine was quantified by gas chromatography. Activity and demographic data were recorded. The average PM2.5 concentration over nine experiments conducted between September 2018 and August 2019 was 840 mu g/m3 (standard deviation of 674 mu g/m3). Concentrations of THC, CBD, and CBN in the particulate matter averaged 79.0 mu g/m3, 0.708 ng/m3, and 8.60 ng/m3, respectively. Nicotine concentrations were below the level of quantification. Although a variety of consumption methods were observed, 91% of the observed consumption events were smoking. The business installed a ventilation system halfway through our study. Before the ventilation system was installed, the average PM2.5 was 905 mu g/m3; afterward, it was 795 mu g/m3. This 12.2% decrease was not statistically significant. Our results show that smoking cannabis indoors can create high concentrations of particulate air pollution, which is known to cause adverse health effects.

Automated summary

By measuring the air in the smoking lounge of a cannabis store, we found that smoking cannabis indoors can create high concentrations of particulate air pollution, which may have adverse health effects.